How exactly does faster disc reading fix lag? The coding is the problem.
There are hundreds of people on the forums saying that the slim does not fix the lag. And these are people who have both a fat, and slim PSP. All versions lag.

And yeah Dancers are insane. I've ran into battles with just Ramza and a Dancer and I've won.
I've got to pick this up again, I still haven't beaten this game yet. =/

Quoted for truth.
The faster disc reading time simply lessens the time for the disc to be read...obviously so shorter times before an attack starts but the game will still run at a consistent half speed for things from throw stone to shadowblade (though Celestrial Stasis/Hastaja and stuff are barely affected). The psp can easily handle FFT, the game was deliberately slowed down for some reason (due to poor programming), it's not due to the attacks, if it were there would be much more variation in the rate of slowdown between attacks.
This whole misconception started with the PSP slim having a faster processor speed, but custom firmware's been doing that on the psp fat for ages anyway and it makes no difference.

I've never really used a bard/dancer so I should probably start at some point, I'll no doubt need them for Onion Knight Level 8 (to put my Onion gear to good use)

By the way, has anybody tried that program that lets you play this game through infrastructure? I would like to know how that works or if anybody has had any success with it.

Xlink kai? Yes I've been using it extensively, in fact most of my recent posts were about my 'adventures' on it, from farming super weapons to defeating all the Lucavi at once in single combat. My kai tag is "GigaShadow" for the record. I don't know how it works but I do know that it tricks your psp into thinking it's playing ad-hoc with people in the same room when it's not.
I've had a lot of success with it, but it can be quite temperamental.
Generally speaking you'll need a "Wifimax" or similar accessory although some routers are compatible with the psp's adhoc without, I have to use the former since I don't have full control over the compatible router in my house.

You can find anything you need in here: http://www.teamxlink.co.uk/forum/viewforum.php?f=37&sid=923c8023b37c640ab36fd9a583e2d3ae